Roadway markers are used on or around roads to convey or display information, such as pavement markings, traffic lanes, road stripes or delineators, etc. Oftentimes, roadway markers include a reflective component so that motor vehicle drivers can clearly see the markers after dark. Reflective roadway markers have the ability to reflect some portion of incident light back towards the source from which the light originated. Motor vehicle headlamps are turned toward the road surface to illuminate, for example, the boundaries of traffic lanes for the motor vehicle driver.
It is known that roadway markers used on a road are subject to wear caused by traffic and other conditions. One manner in which roadway markers become damaged is by the wear caused by snowplow blades. Snowplow blades are designed to clear the roadway of snow and ice and, therefore, preferably continually engage the surface of the road. When a snowplow blade contacts a roadway marker, the blade can impact the marker and components thereof, such as reflective compounds, with sufficient force to break off some of the compounds or portions of the marker and also from the roadway. After a period of time, a sufficient number of reflective compounds can wear off so that reflectance provided by the roadway marker is significantly diminished.
Numerous different approaches have been attempted to provide roadway markers, some with the goal of preventing or minimizing impact by a snowplow blade or reduce wear from the tires of an automobile. Some of the approaches are described for example in U.S. Pat. Nos. 2,897,732; 3,030,870; 3,204,537; 4,758,469; 5,380,549; 5,660,497; 5,676,488; 5,759,928; 5,763,000; 5,782,577; 6,225,371; 6,247,818; 6,431,788; and 7,168,815.
For example, U.S. Pat. No. 6,431,788 relates to pavement marking and methods of making pavement markings in which the pavement markings reportedly exhibit wear resistance to, e.g., snowplow blades. The pavement markings include elongated protuberances in which successive elongated protuberances overlap along at least the longitudinal direction and may also overlap in a direction transverse to the longitudinal axis. Other protuberances are interspersed between the elongated protuberances to reportedly improve retro-reflectivity. The elongated protuberances are provided to reportedly support, e.g., a snowplow blade moving over the pavement marking.
In view of the prior art, there is still a need for an improved method for protecting roadway markers disposed on roadways from wear, such as from forces due to snowplow blades.